This invention related to a jack for telephone sets which, in particular, can perform a function of preventing dust from entering the interior of the jack when it is not used.
The jack of the type referred to incorporates therein terminals for connection of the telephone set to the central office lines and arranged so that, when the jack receives a plug at an end of a cord of the telephone set, plug pins or blades are electrically connected to the terminals in the jack, and is effectively used for such connection of the telephone set of, for example, plug-in type.